1. Field of the Invention
This present invention is directed to systems and methods for removing fluid, e.g. wellbore fluids, water, etc. from a wellbore; to such systems and methods for removing fluid from wells; to such systems and methods for deliquefying, e.g. dewatering, natural gas wells; to hydraulic pump systems for deliquefying a well, and, in certain particular aspects, to pump systems with tubular elongation isolation, inhibition of contamination by solids, flow diffusion, seal enhancement and redundancy, and/or gas build-up release; to such systems that are “power down” systems; and to methods employing such a pump system.
2. Description of Related Art
A variety of systems and apparatuses are known for removing liquid from wells; including, but not limited to, systems for removing produced fluids from wells and for removing inflowing water with solids from producing wells, e.g., from gas wells. Such systems and apparatuses include those disclosed in these exemplary U.S. patents and applications: U.S. Pat. Nos. 2,580,331; 3,227,086; 4,403,919; 4,738,599; 4,485,876; 5,339,905; 6,629,566; 7,789,131; 7,874,367; 7,954,547; and U.S. application Ser. Nos. 12/372,962 filed 18 Feb. 2009; 12/388,098 filed 18 Feb. 2009; and 12/388,542 filed 19 Feb. 2009—all of which are incorporated fully herein by reference for all purposes.
Various known downhole pumping systems employ a production fluid conduit and another conduit for conducting a power fluid, e.g. hydraulic fluid, to a downhole pumping system. During the application of power fluid, high pressure is applied to the power fluid conduit for a period of time, and then this pressure ceases. Downhole at the pump location, the fluid conduits experience the pressure due to the column of fluid above the pump. An increase in pressure on the power fluid line causes the power fluid conduit to expand and strain, both diametrically and axially. The axial expansion increases or elongates the overall length of the power fluid conduit, e.g. in some wells about ten feet of expansion between the surface and the pump. The other fluid conduit, e.g. a conduit for the evacuation of produced fluid from the well, does not expand as much as the hydraulic fluid conduit and the differential in these expansions produces movement of the power fluid conduit with respect to the production fluid conduit which can cause wear problems and helixing or corkscrewing of the conduits. This can result in apparatuses being stuck in a well and in the failure of a pumping system.